you're watching "bbc world news america." still to come on tonight's program, nearly 25 years after a deadly gas attack, one kurdish town is still trying to identify the scores of people who died. to japan now, where the authorities are trying to figure out how tunnel collapsed on sunday, killing at least nine people. huge concrete slabs in the tunnel smashed on to cars. that started a fire on the main route from tokyo to central japan. we report now on that story. >> only this morning, the mangled wreckage of three vehicles was brought -- early this morning, the mangled wreckage of three vehicles was brought from the tunnel. last came a small delivery truck. the driver had been trapped, but alive. by the time rescuers got to him, he was dead. the collapsed tunnel lies deep in the mountains of central japan, just to the north of mount fuji. it is part of the expressway that links tokyo to central and western japan. the tunnel itself is nearly 5 kilometers or 3 miles long. engineers are trying to work out what went wrong. what